Monkey Lunge is a feat introduced in a Pathfinder Companion, and reads as follows:

Prerequisites: Lunge, Acrobatics 1 rank.

Benefit: As a standard action, you can use the Lunge feat to increase
the reach of your melee attacks by 5 feet until the end of your turn,
without suffering a penalty to your AC. You cannot use this feat if
you carry a medium or heavy load.

Normal: You take a -2 penalty to your AC until your next turn when
making a lunge attack.

Is there ever any use for this feat?

Given that activating the ability is a standard action, you have only a move action left in your turn, which you cannot use to attack. The ability ends at the end of your turn, which means that after your move action your reach drops back again. Unless someone readied an action to charge you after you used Monkey Lunge (thus provoking during the middle of your turn - an incredibly odd readied action indeed) I do not see how you would ever be able to use this feat and make an attack with it.

1 Answer
1

This is conjecture on my part, but it's likely an error in the feat description. Compare with the Lunge feat that this "improves" on, which states:

You can strike foes that would normally be out of reach.

Prerequisites: Base attack bonus +6.

Benefit: You can increase the reach of your melee attacks by 5 feet until the end of your turn by taking a –2 penalty to your AC until your next turn. You must decide to use this ability before any attacks are made.

Given the description of the "Normal" state upon which Monkey Lunge improves, it appears that the intent of Monkey Lunge is that you no longer take the -2 penalty to AC when using Lunge. The description of Lunge does not state that it is a standard action - it seems likely that the standard action part of the Monkey Lunge feat description is a poor choice of words.